MUST WATCH

JUST WATCHED

Obama: Troops will be home by end of '14

MUST WATCH

A "zero option" has always been among the scenarios the United States envisioned. But the new revelation means that it could be a very possible one now.

Pentagon spokesman George Little said Tuesday that Obama has not made a decision on U.S. troop levels in Afghanistan beyond 2014.

"We are continuing discussions" with Afghanistan about carrying out post-combat missions, Little said. "We continue to work through issues," he said, adding, "We believe we can work through them."

If the United States pulls out all its troops, it will be a situation similar to that in Iraq.

The refusal by the Iraqi government to extend legal protections for U.S. troops after the end of the war in Iraq was a major reason the United States left the country with no residual military training force.

Karzai has said he would like for U.S. troops to remain after the end of the NATO mission. But he also has been highly critical of the troops over the years, following incidents in which U.S. forces have killed civilians.